Is there sufficient evidence for encouraging widespread use of HRT to prevent disease?

Sir, I enjoyed Philip Hannaford's measured and incisive editorial on the use of hormone replacement therapy (HRT) (February Journal). 1 We too have been interested in the issue of using HRT for the prevention of osteoporosis, and have conducted an extensive literature search on the subject as part of a project to develop evidence-based audit criteria for osteo-porosis in primary care. 2 Despite the uncertainty over the long-term benefit/risk ratio of HRT that Hannaford points out, the use of HRT for long-term therapy is widespread and rising. 3 This raises an important issue of whether current medical practice in this area is evidence based and how GPs and other members of the primary health care team can make accurate recommendations that reflect the current state of knowledge. In practice it is helpful to make a distinction between the relatively short-term use of HRT for the relief of climacteric symptoms, such as vasomotor flushing and uro-genital atrophy where the evidence base is strong, 4 and the long-term use for prevention where the evidence is less well established. 1 The cardiovascular benefits conferred by long-term HRT are yet to be firmly established. The evidence for HRT preventing osteoporosis is derived from observational studies, and the impact of fracture rates is not clear. There is evidence from controlled trials of the effect of HRT on bone mineral density. 5 There are risks of HRT such as breast cancer and of venous thromboembolism. However, until long-term large-scale randomized controlled trials of HRT have been reported, universal HRT for the prevention of disease cannot be recommended. A review of the evidence has led us to conclude that the opportunistic, rather than universal, use of HRT is currently the best approach for women aged 44–55 years. It is also worth pointing out that, although HRT is currently the main stay for the prevention of bone loss in women, the situation is changing by advances in drug therapy such as bisphosphonates, which have strong evidence of effectiveness from randomized controlled trials. 6 Together with vitamin D analogues, there are now several non-hormonal treatments for the prevention of osteoporosis. However, the benefit/risk ratio of HRT may alter substantially with the advent of selective oestrogen receptor modulators (SERMs), which may not have same adverse effects of conventional HRT. 7 This debate illustrates the difficulties of making general practice more evidence based, especially when the available evidence is conflicting, uncertain, …